Frequency Selection Expression

token UNIT       of type String
token INT        of type String
token FNUMBER    of type String
token QSTRING    of type String
token REGEX      of type String
token IDENTIFIER of type String

type TEN SpwStatement
type TEN FullSpec
type TEN FullExpr
type Float[2] OneFreq
type Float[2] FreqRange
type Float[2] Physical
type Float[4] IndexRange
type Float[4] PhyRange
type Vector<int>    Spw
type Float[2] FListElements
type Vector<Float>   FreqList
type Float PhyVal


SpwStatement: FullExpr | LPAREN FullExpr RPAREN

PhyVal: FNUMBER

Physical: PhyVal UNIT

PhyRange: Physical TILDA Physical
        | PhyVal TILDA PhyVal UNIT
        | PhyRange CARET Physical 

IndexRange: PhyVal TILDA PhyVal
          | IndexRange CARET PhyVal

FreqRange: IndexRange
         | PhyRange

OneFreq:  PhyVal
        | Physical

FListElements: FreqRange
             | OneFreq

FreqList: FListElements
        | FreqList SEMICOLON FListElements

Spw: IDENTIFIER
   | QSTRING
   | REGEX
   | OneFreq
   | GT OneFreq
   | LT OneFreq
   | TILDA OneFreq
   | FreqRange
   
FullSpec: Spw 
        | Spw COLON FreqList

FullExpr: FullSpec
        | FullExpr COMMA FullSpec